body {
    font-family: Arial, sans-serif;
    margin: 0;
    padding: 0;
    background-color: #f4f4f4;
}

header {
    background-color: #333;
    color: white;
    padding: 10px 20px;
    text-align: center;
}

nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
    background-color: #444;
    color: white;
    padding: 10px 20px;
}

nav ul {
    list-style: none;
    padding: 0;
    margin: 0;
    display: flex;
}

nav li {
    margin-right: 20px;
}

nav a {
    color: white;
    text-decoration: none;
}

main {
    max-width: 800px;
    margin: 40px auto;
    padding: 20px;
    background-color: white;
    box-shadow: 0 0 10px rgba(0, 0, 0, 0.1);
}

h1 {
    color: #333;
    text-align: center;
}

p {
    line-height: 1.6;
}

footer {
    background-color: #333;
    color: white;
    text-align: center;
    padding: 10px 20px;
    position: fixed;
    bottom: 0;
    width: 100%;
}

/* 响应式设计 */
@media (max-width: 600px) {
    nav ul {
        flex-direction: column;
    }

    nav li {
        margin-right: 0;
        margin-bottom: 10px;
    }
}